Spec Update: Batch 03 — Types

Date: 2026-04-16 Plans Referenced: Plan 048 (generics), Plan 052 (List/storage), Plan 120 (Option/Result), Plan 121 (Task/Handle), Plan 155 (String), Plan 160 (Map) Source Files: ast/types.rsSections Updated: Types (Section 5) — major rewrite

Old Content

Old "Basic Types" table listed 15 types in a single flat table:

• Primitives: int, uint, byte, i8, i16, i64, u16, u64, float, double, bool, str, char, void, nil
• No compound types documented (arrays, slices, pointers were in "Type Modifiers" section)
• No Option, Result, Handle, linear, String, Map types

New Content

Primitive Types (15 → 16)

• Added usize (pointer-sized unsigned integer)

String Types (new section)

• str — borrowed string slice
• String — owned dynamic string (Plan 155)
• cstr — C string, null-terminated

Compound Types (new section)

• Static arrays: [N]T (e.g., [10]int)
• Runtime-sized arrays: [expr]T (Plan 052)
• Slices: []T
• Lists: List<T> (growable, heap-backed)
• Maps: Map<K, V> (Plan 160)
• Pointers: *T
• References: &T

Special Types (new section)

• Option: ?T — Some(T) or None (Plan 120)
• Result: !T — Ok(T) or Err(...) (Plan 120)
• Handle: Handle<T> — task reference (Plan 121)
• Linear: linear<T> — move-only semantics
• Function types: fn(params) ret
• Generic instances: MyType<T>, MyType<T, N u32>

Type System Stats

• Total Type enum variants: 37 (from ast/types.rs)
• All 37 variants now documented in spec

Notes

• The old "Type Modifiers" section in "Type Definitions" (postfix [], *, &, ?) is superseded by the new compound types documentation here
• str with a length parameter (Str(usize)) in types.rs represents the literal string length for compile-time tracking; in user code it's just str
• Unknown type variant exists in types.rs but is internal (type inference fallback); not documented as user-facing